Reduction mill



Oct. 26, 1965 R. E. OWENS ETAL REDUCTION MILL 2 Sheets-Sheet l Filed July 18, 1963 Oct- 25, 1965 R. E. owENs ETAL 3,214,105

REDUCTION MILL Filed July 18, 1963 2 Sheets-Sheet 2 INVENTORS.

United States Patent Office 3,214,105 Patented Oct. 26, 1965 3,214,105 REDUCTION MILL Roland E. Owens, Verdon, Nebr., and William W.

Miner, Jr., Union Valley, Halt` Acre Road, Cranbury, NJ.

Filed Jnly 18, 1963, Ser. No. 295,875 9 Claims. (Cl. 241--154) This invention relates to reduction mills and refers more particularly to mills of the swing hammer or im pact type, wherein the disintegration and crushing of materials takes place in a two-compartment housing, the upper compartment containing chopping stages and the lower compartment the inal disintegrating stage.

Conventional impact or hammer mills used for crushing solids, such as coal or ore, have proved relatively unsatisfactory when used for grinding, decorticating and reducing wet, sticky, fibrous products such as bagasse, corn stalks, weeds, tree bark, garbage, coarse sewage screenings, stockyards waste and the like.

The instant invention provides a construction which will reduce waste products of this character whether `Wet or dry, besides being capable of processing large quantities of such material over relatively short periods without clogging or injury to the disintegrating mechanism.

Another object is to provide a construction Whose ntake or charging port is substantially the diameter of the mill itself, thereby eliminating to a great extent the necessity of preseparating or preworking the material to be processed.

A further `object is tot provide a two-stage reduction mill, the rst stage a chopping stage in which a series of rotary beaters of progressively increasing diameter are followed by macerating or disintegrating beaters in the second stage where the impacting units are of substantially the same diameter.

Still another object is to provide a mill which is rugged in construction, easily serviced and repaired and affords long, uninterrupted, economical service, besides being a compact unit with its driving mechanism mounted on a common base and portable, since both the mill and prime mover or motor are supported upon a single skid rail base.

An embodiment of the invention is shown in the accompanying drawings which form a part of the instant specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the Various views.

t- In the drawings, FIG. 1 is an end elevational view of the unit.

FIG. 2 is a front elevational view showing the motor and drive transmission mechanism.

FIG. 3 is a centr-al section taken through the mill showing the chopping and grinding compartments and mechanisms.

FIG. 4 is a view taken along the line 4-4 in FIG. 3 in the direction of the arrows.

FIG. 5 is a detail of one of the bearing supports or struts placed 120 apart in the housing to carry the upper bearing.

FIG. 6 is a view taken along the line 6-6 in FIG. 5 in the direction of the arrows.

FIG. 7 is a view taken along the line 7-7 in FIG. 6 in the direction of the arrows.

FIG. 8 is a view taken along the line 8-8 in FIG. 2 in the direction of the arrows.

FIG. 9 is a view taken along the line 9-9 in FIG. 3 in the direction of the arrows.

Referring to the drawings, the reduction mill or crusher comprises a hopper 10 having side and top openings of a size substantially the diameter of the mill, for the introduction or charging of material -to be disintegrated or crushed. The hopper is mounted upon the mill housing 11, which in turn is supported by legs 12 and angle iron skids 13. An inspection door 14 is hinged in the side of the housing to give access to the crushing mechanism. A spiral vane or baille 15 is welded to the inside surface of the hopper and extends into the top of the upper compartment of the mill. This baie serves to prevent accumulation and clogging of the charged material in the hopper portion of the mill. The hopper 10 and housing 11 are fastened together to form a unitary structure by iianging the lower edge of the hopper and the upper edge of the mill housing and welding or otherwise uniting the two parts together.

The mill is preferably lined with a shell of hardened steel shown best in FIG. 3 at 11a, better to withstand the impact of material thrown by centrifugal force by the crushing mechanism and friction and abrasive action of the material being reduced.

In an aperture centrally of the housing bottom 11b is bolted or otherwise fastened roller bearing 16, which, with bearing 17 supported by struts 18, carry shaft 19 upon which the crushing mechanism is mounted. Attached to the bottom end of the shaft 19 is a V-belt pulley 20 over which runs a V-belt 21 shown in dotted lines of FIG. 2. Power is transmitted from the motor 22 through its pulley 23 and V-belt 21 to pulley 20 on shaft 19. y

A discharge opening llc, shown in FIG. 3, is supplied in the side of the housing adjacent bottom plate 11b. The crushing mechanism of the mill is located in two compartments separated by bearing struts 18 and roller bearing 17. In the upper compartment is located the chopping mechanism comprising ilails or hammers 23 pivoted to rotor plates or arms 24a and 24b and 24o by means' of pins 25. These pins are held in place by,

stop plates 26 located beneath the arms and positioned below the ends ofthe pins 25. I

The arms are xedly attached to a torque tube 27 having reinforcement rings at the top andbottom which are fixedly keyed to the shaft 19. The upper rotor arm 24a has a circular body with short diametrically opposed extensions projecting outwardly therefrom. Pivot pins 25 near the ends of these extensions carry the upper bank of hammers 23. The next rotor plates or arms below numbered 24b and 24C are roughly star shaped, the blunt ends or points of the stars being apart as shown in FIG. 4. Hammers or ails 23 are attached to the plates on -pins 25. The two lower arms 24e are of the same diameter and of somewhat greater diameter than arm 24b, as shown in FIGS. 3 and 4. Thus we have in succession from top to bottom three banks of flails or hammers, two diametrically opposite in the upper bank and four 90 apart in the second and third bank. The diameter of each bank of hammers 23 increases from t-op to bottom, the ends of the upper hammers extending substantially one-half of the radius of the housing, the ends of the second bank of hammersV about one-half the distance between the ends of the first bank and the inside of the housing and the ends of the lower bank extending almost to the housing lining with snicient clearance for free rotation.

In the lower disintegrating compartment below the bearing 17 and tixedly attached to the lower portion of the shaft 19 is torque tube 28 constructed similarly to tube 27 but `of larger diameter. Fixedly attached to the periphery of the torque tube 28 at the top and bottom are two disk-shaped arms 29 and three intermediate starshaped arms 29a positioned between the upper and lower disks 29 as shown in FIGS. 3, 4 and 8. Near the ends of these arms are pivoted hammers or iiails 30 upon pins 31, which extend through the arms from top to bottom and are held against displacement by stop plates 32 beneath the lower disk 29. The ends of the hammers 30 have about the same clearance with the inside of the housing as do flails 23 in the upper compartment. A spacer ring 33 is located around the bearing 16 between the housing and bottom of the torque tube to prevent the entry of dirt and grit into the lower bearing.

In order to supply a rigid support for the bearing 17, the struts 18 are extended through the housing, and are bolted or otherwise fastened to brackets outside of the housing, as shown in FIGS. 4, 5 and 6. Upon these struts or bearing supports 18, which separate the upper and lower compartments, are attached dellectors 38, shown in FIGS. 4, 5, 6 and 7. These deectors are positioned just inside of the housing on the leading edge of the struts, as shown in FIGS. 4, 6 and 7, and serve to deflect the partially crushed and separated material chopped in the upper compartment into the lower grinding compartment.

It has been found that improved results may be obtained particularly in the lower disintegrating or grinding compartment of the mill and when crushing or distintegrating certain types of materials to contour or distort some of the ilails or hammers by twisting them axially, as shown in FIG. 9.' Also a down turned flange formed on the bottom row of hammers, as shown in FIG. 9, assists in moving the ground material toward the discharge outlet 11C. A similar result may be obtained by fastening a sweep strip, not shown, radially across the underside of the lower disk arm 29a.

To govern the particle size of the material crushed and ground in the lower compartment, adjustment plates 34 are itted diametrically opposite in the housing as shown in FIGS. 2 and 8. The plates are preferably rectangular in shape, of hardened steel and located opposite the ends of hammers 30. They are adjustable inwardly or outwardly with respect to the inside surface of the housing by adjusting screws 35, threaded to t nuts 35a, attached to holding plates 36 and hex-headed set or back up screws 37.

In the reduction of waste products such as city garbage, coarse sewage screenings, brous materials of wood, cardboard, box board or the like, the products to be ground are tossed into the hopper and fed to the chopping and crushing mechanism in the upper compartment of the mill. By scaling the separate stages in the compartment from a small diameter impact device at the top to successively larger diameter stages below, the materials processed are progressively disintegrated without excessive stress, strain or duty upon the impact mechanism. The design of the arms and hammers in this upper chopping or crushing compartment presents and aids the products being processed to move smoothly and rapidly downward through the upper compartment where they are delivered by the actions of the dellectors 38 to the grinding or disintegrating compartment below.

- In the distintegrating compartment they are again subjected to an eflicient impact mechanism or hammer mill of unique design and rugged construction which again reduces the materials to the size desired for disposal by incineration or further processing such as composting or the like.

The mill is of rugged construction with parts that are easily accessible for replacement and can be operated continuously with a minimum of down time.

From the foregoing it will be seen that the invention is well adapted to attain all of the ends and -objects hereinbefore set forth together with such other advantages as are obvious and which are inherent to the structure.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

1. A a reduction mill of the character described comprising Ia rotor housing having top inlet and bottom discharge openings,

partition bars separating said housing into upper chopping comparment and a lower disintegrating compartment,

a vertical shaft positioned centrally of the compartments and rotatable in bearings supported in the housing,

driving means mounted on the lower end of the shaft,

a series of banks or stages in the upper chopping compartment including rotor plates rotatable with the shaft and flails pivoted peripherally to said plates, each successive chopping stage of greater diameter than the one above,

distintegrating elements in the lower compartment including rotor arms rotatable with the shaft,

a series of ail members pivoted at the extremities of the rotor arms,

the overall diameter of said disintegrating members being less than the interior diameter of the housing and substantially that of the lower bank of ails in the upper chopping compartment.

2. A reduction mill as in claim 1, including a torque tube fixedly attached to the shaft in both the upper and lower compartments, said tubes providing intermediate mountings between the shaft and rotor plates in the upper compartment and the shaft and rotor disks in the lower compartment.

3. A reduction mill as in claim 2, in which the torque tube in the lower compartment is of greater diameter than the torque tube in the upper compartment.

4. A reduction mill as in claim 2, wherein an upper shaft bearing is positioned between the upper and lower torque tubes and a lower shaft bearing is positioned beneath the lower torque tubes.

5. A reduction mill as in claim 1, wherein the flails of the chopping stages in the upper compartment are individually pivoted to the rotor plates while the disintegrating flail elements in the lower compartment are pivoted at the extremities of the arms in groups upon single pivots.

6. A reduction mill as in claim 1, with deflectors on the partition bars between the upper and lower compartments.

7. A reduction mill as in claim 1, in which the flails of the upper bank in the chopping compartment extend substantially one-half of the radius of the housing,

the ails of the intermediate bank extend about onehalf the distance between the ends of the ails of the upper bank and the inside surface of the housing, and

the llails of the lower bank extend almost to the interior housing surface or lining with sufficient clearance for free rotation.

8. A reduction mill of the character described comprlsmg a rotor'housing having top inlet and bottom discharge openings,

partition bars separating said housing into an upper chopping compartment and a lower disintegrating compartment,

a vertical shaft positioned centrally of the compartments and rotatable in bearings supported in the housing,

driving means mounted on the lower end of the shaft,

a series of banks of flail elements rotatable with the shaft in the upper chopping compartment, each of said banks being of increased diameter from top to bottom, and

5 a series of banks of ail elements rotatable with the shaft in the lower disintegrating compartment, said banks of disintegrating flails being of like diameter and corresponding to the lowest bank of ail elements inthe chopping compartment.

9. A reduction mill as in claim 8, including adjustment plates inset into the interior wall surface of the disintegrating compartment opposite the ends of the tlail elements and means for radially adjusting said plates from the exterior of the housing for governing the particle size of the material processed.

References Cited by the Examiner UNITED STATES PATENTS 4/39 Rietz 241-86 11/43` Harris.

2/ 51 Rietz.

8/57 Chayen 146-182 X 9/57 Records 241-191 X 8/58 Brophy 241-154 X FOREIGN PATENTS 5/59 Germany.

J. SPENCER OVERHOLSER, Primary Examiner. 

1. A A REDUCTION MILL OF THE CHARACTER DESCRIBED PRISING A ROTOR HOUSING HAVING TOP INLET AND BOTTOM DISCHARGE OPENINGS, PARTION BARS SEPARATING SAID HOUSING INTO UPPER CHOPPING COMPARMENT AND A LOWER DISINTEGRATING COMPARTMENT, A VERTICAL SHAFT POSITIONED CENTRALLY OF THE COMPARTMENTS AND ROTATABLE IN BEARINGS SUPPORTED IN THE HOUSING, DRIVING MEANS MOUNTED ON THE LOWER END OF THE SHAFT, A SERIES OF BANKS OR STAGES IN THE UPPER CHOPING COMPARTMENT INCLUDING ROTOR PLATES ROTATABLE WITH THE SHAFT AND FAILS PIVOTED PERIPHERALLY TO SAID PLATES, EACH SUCCESSIVE CHOPPING STAGE OF GREATER DIAMETER THAN THE ONE ABOVE, DISTINTEGRATING ELEMENTS IN THE LOWER COMPARTMENT INCLUDING ROTOR ARMS ROTATABLE WITH THE SHAFT, A SERIES OF FAIL MEMBERS PIVOTED AT THE EXTREMITIES OF THE ROTOR ARMS, THE OVERALL DIAMETER OF SAID DISINTEGRATING MEMBERS BEING LESS THAN THE INTERIOR DIAMETER OF THE HOUSING AND SUBSTANTIALLY THAT OF THE LOWER BANK OF FAILS IN THE UPPER CHOPPING COMPARTMENT. 